1. Field of the Invention
The invention relates to a patient handling system for medical diagnostic imaging systems. More particularly the invention relates to a modular patient handling system with a patient table affixed to and spanning a diagnostic imaging system support base within the imaging field of view, and including a conveyor for transporting patients in and out of the imaging system field of view.
2. Description of the Prior Art
As shown in FIGS. 1 and 2, existing medical diagnostic imaging apparatus 10′ includes an imaging system 20′ with a field of view (FOV) established within patient receiving tunnel or bore 22′. Exemplary imaging system modalities include X-ray radiography or fluoroscopy, computed tomography (CT), positron emission tomography (PET), single photon emission computed tomography (SPECT), ultrasound, or magnetic resonance imaging (MRI). Existing diagnostic imaging apparatus 10′ may incorporate more than one imaging modality: often oriented with adjoining fields of view within the patient receiving bore 22′.
The imaging apparatus 10′ includes a support base 30′ that is rigidly affixed to an imaging center floor. The floor is often constructed of reinforced poured concrete. During installation of an imaging apparatus 10′, the support base 30′ is often affixed to a floor at designated mounting points by precision drilling of an array of holes into the concrete, followed by precise insertion and embedding of threaded rods into the holes with epoxy or other permanent bonding media. The support base 30′ structure is then affixed to floor mounting points by engaging the embedded threaded rods with mating threaded fasteners. Creation of a precision array of holes and subsequent threaded rod embedding is complex and time consuming. Imaging apparatus 10′ installation effort is roughly proportional to the number of mounting points that must be installed for a support base 30′ footprint. The support base 30′ of FIG. 1 includes a separate and distinct floor-mounted extension portion under cantilevered patient table 40′, in order to counteract deflection forces caused when a patient is placed on the table. The floor-mounted extension portion of support base 30′ consumes additional floor space that is not needed for support of the imaging system 20′ and inhibits maneuvering of patient gurneys or transport beds close to the imaging apparatus 10′.
The patient table 40′ includes a cantilevered table frame 42′ mounted external the imaging system 20′ and its related portion of the support base 30′. The table frame 42′ includes a rail structure (not shown) for engagement with a reciprocating/translating patient bed 50′ that is cantilevered into the patient bore 22′. Thus the frame 42′ is in effect a cantilever beam that is in turn supported from the oppositely directed cantilevered patient table 40′. The patient table 40′ a vertical height adjustment capability that is schematically shown as ΔY in FIG. 2. The patient bed 50′ is translatable horizontally and vertically under control of a servo motor system (not shown) within the imaging system bore 22′, on the frame 42′ rails, so that the patient can be aligned selectively within the field of view. The table frame 42′, its rail structure, vertical height adjustment and the reciprocating patient bed 50′ project a minimum height H within the diameter D of the patient bore 22′ and thereby adversely reduces available inspection volume within the patient bore (i.e., it reduces the volume in which a patient can be oriented). Reduced available inspection volume reduces patient maneuvering flexibility within the patient bore 22′—especially for larger patients.
Patient weight impacts cantilever deflection loads on the patient table 40′. Excessive weight deflection loads can cause unwanted vertical movements (often referred to as “porpoiseing”) that can cause image distortion during diagnostic scanning procedures. Weight deflection is often countered in patient table 40′ design by utilization of larger and higher strength components within the imaging system 20′ field of view that may also adversely cause so-called “ghost” or “artifact” image distortion.
During an imaging procedure with the imaging apparatus 10′ a portion of a patient that is being imaged is inserted into the patient bore 22′ with the patient in a generally supine position. The patient is transferred to the imaging apparatus 10′ while the patient bed 50′ is extended distally from the patient bore 22′, as shown in FIG. 1. When initially transferred to the patient bed 50′ a relatively ambulatory patient is seated on a lateral edge of the bed and then oriented in a supine position so that the bed and patient thereafter can be translated into the patient bore 22′. Non-ambulatory patients must be transferred laterally from a gurney or other mobile bed to the patient bed 50′, with the assistance of medical personnel. Patient transfers to the imaging system 10′ patient bed 50′—whether ambulatory or non-ambulatory—can cause patient discomfort and are relatively laborious for assisting medical personnel.
A proposed patient positioning solution in U.S. Patent Publication No. US 2011/0092792, published Apr. 21, 2011, incorporates a motorized conveyor belt oriented through both sides of an imaging system bore. The conveyor belt is placed on a support platform that bridges the imaging system bore and is supported vertically on both sides of the bore by external columns that are affixed to the imaging room floor. External columns require the aforementioned construction costs and efforts necessary for affixing them to the imaging room floor. The external columns also have the aforementioned problems of consuming floor space and inhibiting maneuvering of patient transport beds proximal to the imaging apparatus. The known conveyor belt construction has the same aforementioned patient transferring challenges regarding ambulatory and non-ambulatory patient placement on the conveyor belt.
Thus, a need exists in the art for a medical diagnostic imaging apparatus patient table that is capable of supporting a larger patient weight load without causing excessive load deflection within or external the patient bore that can adversely impact image quality.
Another need exists in the art for a medical diagnostic imaging apparatus patient table that is capable of supporting a larger patient weight load without increasing component size within the imaging field of view that might otherwise adversely impact image quality.
An additional need exists in the art for a medical diagnostic imaging apparatus patient table that increases available patient imaging volume within a given size imaging system patient bore.
Yet another need exists in the art for a medical diagnostic imaging apparatus patient table that does not require installation and affixation of dedicated patient table external support structure to the imaging room floor.
Another need exists in the art for a medical diagnostic imaging apparatus patient table that facilitates easier transfer of ambulatory or non-ambulatory patients to the table.